In a speech today at the Navy League symposium, Gates said the service needed to take another look at plans to keep 11 carrier strike groups for the next three decades. "In terms of size and striking power, no other country has even one comparable ship," Gates noted.

"To be sure, the need to project power across the oceans will never go away," he said. "But, consider the massive over-match the U.S. already enjoys. Consider, too, the growing anti-ship capabilities of adversaries. Do we really need eleven carrier strike groups for another 30 years when no other country has more than one? Any future plans must address these realities."

It's a message the Navy has thus far been resistant to. The service has taken some steps to buy smaller, faster shore-hugging ships, and has also embraced riverine operations for the first time since Vietnam. But Gates suggested that the service was still wedded to multi-billion-dollar ships that may in the future be increasingly vulnerable. The aircraft carrier may be the ultimate symbol of American military power. But with the right missile aimed at it, a carrier can go from fearsome to fearful sitting duck in a hurry.

"The virtual monopoly the U.S. has enjoyed with precision guided weapons is eroding – especially with long-range, accurate anti-ship cruise and ballistic missiles that can potentially strike from over the horizon," he said.

That point should be familiar to Danger Room readers: As we've noted here before, China has been testing anti-ship ballistic missiles designed specifically to target aircraft carriers. And as ships rise in price – like the next-generation, Ford-class carrier under construction here – cost itself becomes a vulnerability. A Ford-class carrier with a full complement of aircraft, Gates noted, "would represent potentially $15 to $20 billion worth of hardware at risk."

And that's overkill when it comes to many kinds of maritime threats the Navy now faces. "In particular, the Navy will need numbers, speed, and the ability to operate in shallow water, especially as the nature of war in the 21st century pushes us toward smaller, more diffuse weapons and units that increasingly rely on a series of networks to wage war," he said. "As we learned last year, you don’t necessarily need a billion-dollar guided missile destroyer to chase down and deal with a bunch of teenage pirates wielding AK-47s and RPGs."